Latin America is definitely much more different than all other regional groupings called urban southern continent (75%). Over 40% of South Americans live in cities and the mainland millionaires in four megacities of more than 10 million people. This originality can be explained by the age of the urban presence and by the end of the 18th century, with 15% urban population. Latin America was the most urbanized region in the world. Even if Columbia left traces, it is colonization that installed the existing urban fabric of the network. The urban transition has promoted the early emergence of very large cities, and was strengthened by a process which accelerated metropolization and the concentration of urban populations and functions in a small number of primate cities.